« back to encyclopedia search results
Irradiation of Food
A method of preserving food by subjecting it to low-strength gamma ray treatment from cobalt 60 or cesium 137, thus destroying micro-organisms. Private research on irradiation was begun in 1946 by M.I.T., Electronized Chemicals Corporation and General Electric.
The fact that families increasingly had fridges during the 1950"s and 60"s curtailed much more development, as costs were high. However, it has emerged during the 1990"s as a way of extending the shelf life of certain fruit and vegetables - strawberries, for example, can have their shelf life dramatically extended if treated in this manner.
What is known, is that irradiation disrupts molecule bonds, which can recombine with other molecules, and this can produce new substances called radiolytic products, which poses a question of safety since they are impossible to test.
Irradiation destroys certain nutrients in the food such as vitamins A, B, C, E and K.
Although the process is legal in some countries, uncertainty remains about possible long-term effects on consumers from irradiated food. Its long- term use remains in the balance, but food that has been irradiated, must be labelled as such.
At the present time, March 2003, the U.S.A is investing at full steam in irradiation technology - and food treated in this way is treated as normal (they tend to use the term X ray technology); but research in Europe by the 'Scientific Committee on Food', has shown that doses over 10kGy causes cancers in rats (if they are fed foods so treated), and despite pressure this remained the maximum permitted limit.
However, a meeting of the 168 nations belonging to Codex, which took place in Rome in July 2003, decided there should from now on be no upper limit on the amount of radiation permissible - 10 countries voted against this, but Britain was notably not one of them! See 'Scientific Committee on Food'